The Passenger Pigeon's Story: What Can We Learn from Its Extinction?
Updated: Apr 21, 2020
sun blotted out, scores
and scores of pigeons — hunted
and forever lost
The passenger pigeon’s story is both amazing and incredibly sad. This bird was once the most numerous bird in North America, possibly even the most numerous bird in the world. In a remarkably short amount of time the bird went from a population of 3 – 5 billion in the 1800s, to extinct in 1914.¹ From staggering numbers to completely gone; the decline to extinction occurred in just 30 years.²
The passenger pigeon was a large pigeon similar in appearance to the mourning dove that is still common in North America but much larger, with a longer tail. The passenger pigeon’s neck feathers were iridescent, appearing orange or red and bluish slate at some angles, but metallic pink or violet with metallic gold and green iridescence from other angles. Like other pigeons and doves, the passenger pigeon had a sleek body, built for aerial speed and endurance and was estimated to have a normal flight speed of 100 km/h.³
The birds were nomadic, moving from food source to food source in massive colonies with seeds and fruit making up the majority of their diet. The range of the passenger pigeon was from the Great Plains and Canadian Prairies, east to the Atlantic Ocean. They resided as far south as Texas with some reports in Mexico and reports as far north as Canada’s Northwest Territories.⁴ This bird was the most numerous bird in North America with estimates from 3 – 5 billion birds. To help understand this number, currently the most numerous bird in North America is the mourning dove with a total population of about 350 million individuals.⁵ That’s only about one tenth of the population of passenger pigeons that once flew about our continent.
One of the most distinctive and amazing characteristics of the passenger pigeon was the huge colonies they lived in. Flocks of immense size would fly from forest to forest in search of food or a nesting area. The huge size of their colonies acted as a defense mechanism as no predator could even make a dent in their numbers before being completely satiated. Seeing one of these flocks in the 19th century would have been quite a spectacle.
One day birding near Alberta’s Beaverhill Lake, my wife and I saw an estimated 7200 sandhill cranes migrate overhead. This is a sight I will always remember, there were so many birds. Crane after crane flew overhead. This experience, however, pales in comparison to what it would have been like to experience a flock of passenger pigeons flying overhead.
Passenger pigeons were in huge colonies almost exclusively. The colonies numbered at least hundreds of thousands of breeding pairs with estimates in the millions. The massive colonies flew in such dense formations that when one of these flocks flew overhead, the sky went black, the sun blotted out.⁶ John James Audubon observed these amazing birds and attempted to estimate the number of birds in a flock.
“It may not, perhaps, be out of place to attempt an estimate of the number of Pigeons contained in one of those mighty flocks .. Let us take a column of one mile in breadth, which is far below the average size, and suppose it passing over us without interruption for three hours, at the rate .. of one mile in the minute. This will give us a parallelogram of 180 miles by 1, covering 180 square miles. Allowing two pigeons to the square yard, we have one billion, one hundred and fifteen millions, one hundred and thirty-six thousand pigeons in one flock.”⁷
The number of birds is unimaginable. To get a better understanding of how this visually would have appeared, the following is a simulation from Lost Bird Project of what a flock flying overhead would have looked like.
The Decline to Extinction
With the sheer number of birds that existed it is hard to believe that in a short time, the passenger pigeon went from the most numerous bird in North America, to extinct. By the mid 1890s the great flocks of passenger pigeons numbered dozens of birds instead of the millions they numbered just decades before and the birds were extinct in the wild by 1900. The last captive bird, Martha, died on September 1, 1914 at the Cincinnati Zoo.⁸
There are three key components that led to the extinction of the passenger pigeon: hunting, habitat loss, and their reliance on vast numbers.
Passenger pigeons were hunted for food as long as they lived side by side with humans. Aboriginal people hunted them through netting but had a very limited impact on their numbers and the practise was presumed to be in a sustainable balance.⁹ The problem occurred when Europeans began hunting the birds for food in huge numbers. The behaviour of the birds and the huge, dense flocks they moved in made them very susceptible to being hunted with guns.
A single shotgun blast could kill dozens of pigeons, even as many as 200 – 300 birds with one shot. The number of pigeons harvested in the late 19th century was astronomical. To get an idea, there are records of one Wisconsin pigeon dealer in 1883 shipping two million birds to market in a single year and one hunt of nesting birds in 1851 in Plattsburg, New York, shipped 1.8 million passenger pigeons to market to be consumed.¹⁰ The hunting was not restricted to just shooting, either. Birds were netted in huge numbers and young birds were even killed by knocking them down from their nests with poles or clubs, cutting down the trees that contained occupied nests, burning sulfur below nests to daze the birds, or even lighting the bark of birch trees on fire to force the young out of the trees.¹¹
The hunting of the passenger pigeons not only harmed the species through the direct killing of birds, the birds were also impacted by the large disruption the hunts had to their nesting success due to birds abandoning their nests after being disturbed by hunting.¹² Decreased numbers through hunting combined with decreased breeding success was a potent combination that contributed to the decimating of passenger pigeon populations.
Birds were killed for sale to markets until at least 1893, and reports of birds being shot continued until the end in 1900 when the last recorded wild bird was shot and killed.¹³
Hunting was a major factor in the extinction of the passenger pigeon but habitat loss also had an impact. The large deciduous forests that passenger pigeons required for nesting and foraging were being cut down in the 1800s. The massive forests of eastern North America were cleared for farming, reducing the amount of suitable habitat. Passenger pigeons were less able to adapt to the smaller fragmented forests than other species as the size of their flocks required large forests to support. This one-two punch of hunting and deforestation impacted the numbers of passenger pigeons immensely.
Reliance on Vast Numbers
The passenger pigeon evolved to survive in massive colonies. Their main defense mechanism from predation was sheer numbers. When the populations declined, characteristics of the species such as their conspicuous roosting and breeding behaviours were easily exploited by predators.¹⁴
As well, their nomadic method of finding food relied on large numbers of birds.¹⁵ Again, when populations declined, the birds were unable to as successfully find food sources.
Another way in which passenger pigeons relied on their large numbers was in how they raised their young. When the offspring of the passenger pigeons were about two weeks old, the adults flew away, the young still in the nests. Soon the young jumped from the nests and were vulnerable on the ground for a day or two before they could fly. Predators took advantage of this and preyed on the vulnerable chicks but due to the sheer number of chicks, only a small percentage were killed.¹⁶
The drastic change in flock sizes in a very short time put the passenger pigeon in a position where populations could not recover. A tipping point was reached in the second half of the nineteenth century and as populations decreased more and more, the rate of decline also increased.
The combination of hunting and habitat loss, compounded by the species’ reliance on large colonies, led to the extinction of this beautiful bird.
What Can We Learn?
The passenger pigeon is gone. Nobody will ever again see the amazing flocks flying overhead or hear the thunderous sound of millions of birds flying above. But what can be learned from this tragedy and how can we apply these learnings to future conservation?
One lesson that we can pull from the passenger pigeon’s extinction is that abundance is not necessarily a measure of the resilience of a species. It is crucial that we look at all threats to a species and trust the science, even when it seems anecdotally that the science is wrong. The downfall of the passenger pigeon could have been predicted and prevented with proper research, proper monitoring, and a proper risk assessment. The fall of the species was easy to overlook when there was still an apparent abundance of birds.
A second lesson we can learn is that other nomadic species may also be especially susceptible to loss of suitable habitat such as the crossbills that search out pine or spruce forests of North America to forage and breed. To protect species like this we need to consider the size of the reserves we are protecting to ensure they are sufficient for breeding and foraging of the nomadic species we are trying to protect.¹⁷
Lastly, I believe the most important thing to learn from the passenger pigeon is how fragile nature can be. It is easy to assume that people are insignificant in the grand scheme and won’t make a sizable impact on our environment. The story of the passenger pigeon shows us otherwise. We can and we do have an impact on the environment around us. It is up to us to be responsible in how we treat the natural world. Let us learn from our mistakes and become better stewards for our world. Let us learn from the story of the passenger pigeon.
1. Hung, C. M., Shaner, P. J. L., Zink, R. M., Liu, W. C., Chu, T. C., Huang, W. S., & Li, S. H. (2014). Drastic population fluctuations explain the rapid extinction of the passenger pigeon. Proceedings of the National Academy of Sciences, 111(29), 10636-10641.
2. Blockstein, D. E. (2002). Passenger Pigeon (Ectopistes migratorius), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.611
3. Blockstein, D. E. (2002). Passenger Pigeon (Ectopistes migratorius), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.611
4. Blockstein, D. E. (2002). Passenger Pigeon (Ectopistes migratorius), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.611
5. Sundstrom, B.(2014). Most abundant bird on the continent? Birdnote. Retrieved from https://www.birdnote.org/show/most-abundant-birds-north-america
6. Fuller, E. (2014). The passenger pigeon. Princeton University Press.
7. Audubon, J. J. (1832). Ornithological biography (Vol. 1).
8. Blockstein, D. E. (2002). Passenger Pigeon (Ectopistes migratorius), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.611
9. Fuller, E. (2014). The passenger pigeon. Princeton University Press.
10. Cokinos, C. (2009). Hope is the thing with feathers: a personal chronicle of vanished birds. Penguin.
11. Fuller, E. (2014). The passenger pigeon. Princeton University Press.
12. Bucher, E. H. (1992). The causes of extinction of the passenger pigeon. In Current ornithology (pp. 1-36). Springer, Boston, MA.
13. Blockstein, D. E. (2002). Passenger Pigeon (Ectopistes migratorius), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.611
14. Hung, C. M., Shaner, P. J. L., Zink, R. M., Liu, W. C., Chu, T. C., Huang, W. S., & Li, S. H. (2014). Drastic population fluctuations explain the rapid extinction of the passenger pigeon. Proceedings of the National Academy of Sciences, 111(29), 10636-10641.
15. Bucher, E. H. (1992). The causes of extinction of the passenger pigeon. In Current ornithology (pp. 1-36). Springer, Boston, MA.
16. Fuller, E. (2014). The passenger pigeon. Princeton University Press.
17. Bucher, E. H. (1992). The causes of extinction of the passenger pigeon. In Current ornithology (pp. 1-36). Springer, Boston, MA.